All at sixes and sevens
means in a muddle and a rose from the disagreement described below.

In 1327 the two Livery Companies of Merchant Taylors and Skinners were chartered within a few days of one another, taking places six and seven in the Lord Mayor’s procession. Each reckoned that they were the senior and therefore should have place six and the other should take place seven. The dispute rumbled on until 1484, when they went to the then Mayor, Sir Robert Billesden, and the Aldermen for an adjudication. With positively Solomon-like wisdom he decreed that each company should dine the other annually, and that in that year the Skinners should be at place six, with the Merchant Taylors at place seven: the following year, the Merchant Taylors should take place six and the Skinners place seven. So in even years the Skinners are at six, and in odd years the Merchant Taylors are at six.

(Information provided by Anthony Payne OMT, who also told me that

“Sixes and Sevens” Rugby matches are still played between teams found from the two Merchant Taylors’ Schools (Moor Park and Crosby) and the three Skinners’ schools (The Judd, Tonbridge School and the Skinners’ School)’.  In a recent match the Merchant Taylors’ team won by 22-7.

File:Lord Mayor's Show (Canaletto).JPG
Lord Mayor’s Show by Canaletto
Photo credit Wikimedia Commons‎ (public domain)

It isn’t what you know, but who you know that matters.
Having good contacts is always useful!

There’s safety in numbers.
This is a proverb.  The idea is that it is safer to be in a larger group than one or two people.  In a group of three people, if one is hurt the second can go for help and the third stay with the casualty, for instance.  This may seem an irrelevant example now with mobile (cell) phones, but there are still wild and lonely places where there is no signal.  I’m sure you can think of other situations, where this maxim will continue to be helpful.

The more the merrier
is a reply to the question, “Is it all right if I bring a friend?”

In penny numbers
means a few at a time.  It is an old phrase, pre-decimal, and there were twelve pennies (12d.) in a shilling.  Now there are one hundred (100p) in a pound.

A common factor
is a number which divides exactly into two or more larger numbers.  The term has been borrowed from mathematics to apply to everyday life.

The lowest common denominator
is a similar term from mathematics.   If there is more than one common factor, the lowest common denominators would be the smallest.  For instance, 12=1 x 12=2 x 6=3 x 4  so the lowest common denominators are 1,2,and 3 (4=2 x 2 and 6= 3 x 2)  12=1 x 2 x 2 x 3

Numerical order
may be ascending or descending.

A countdown
is mostly associated with launching rockets and ends with zero.

They would stop at nothing.
This means that there is nothing they wouldn’t do, legal or illegal.

Lightning doesn’t strike in the same place twice.
A saying, which is likely to be true if risk analysis is used.  Figuratively, it means that the same misfortune is unlikely to happen to the same person more than once.  In this case, experience shows that this is not always true.

“One little second” is supposed to take a second to say.

One elephant, two elephants…
…is how my parents taught me to count seconds.

A stopwatch
is a more reliable method.  There is even one on my phone!

Counting sheep
is a recommended method for going to sleep.  I don’t think it works.

Thick and fast and thick and furious have similar meanings.  They remind me of a blizzard, but snowflakes are not the only things to arrive thus.

Snowballing could be a snowball fight, but is more often used to describe something which grows in the way a snowball does, when rolled downhill.

To go off the boil is what a pan or kettle does, if the heat applied is insufficient.  Someone, who has an idea and then loses enthusiasm for it, has gone off the boil.

It’s the tip of the iceberg.
The part that is apparent now is only a fraction of the whole.

It’s the thin end of the wedge
which leads to something bigger.

Nature abhors a vacuum
was the explanation I was given for plants growing to fill any available space.  Fluids moving to a place where the pressure is lower is another more literal example.

I can’t be in two places at once
unless the places are contained inside each other.  The typical schoolchild’s address takes this to its limits.  Have you ever heard the expression, “Not being a bird, I can’t be in two places at once”?

In the Bible King Solomon asked God for wisdom.  He wrote many of the proverbs in The Book of Proverbs.  A well-known story about his judgment concerning who was the real mother of a baby (long before DNA matching) can be found in the First Book of Kings chapter 3 verses 16 to 28.